Perylentetracarboxylic acids and their derivatives and process of making them



insane Patented Aug. 26. 192 i.

MAXIMILIAN P. SCHMIDT AND WILHELM NEUGEBAUER, OE BIEBRICE-ON-THE- RHINE, GERMANY, ASSIGNORS TO THE FIRM KALLE & 00., AKTIENGESELLSGHAFT,

OE BIEBRICH, B-HINE, GERMANY.

PERYLENTETRACARBOXYLIC ACIDS AND THEIR DERIVATIVES AND PROCESS UB1" MAKING THEM.

N Drawing.

TlClltlOIl.

ife have found that by treating the coloring matters. obtainable by melting an imid of naphthalene-l.8dicarboxylic acid or its derivatives with alkaline agents and-oxidizing it necessary. With strong sulfuric acids at a higher temperature, the corresponding mono-imids of the perylentetracarboxylic acids or the perylentetracarlooxylic acids themselves are formed. If

the reaction takes place for a shorter time and a lower temperature, of about 180- l90 centigrade the monoimids of the perylentetracarhoxylic acids are obtained, Whereas a higher temperature of about 2104240 centig'rade the per 'lentetracarhoirylic acids are formed. For instance from the dye-stud described in Example 2 of the American specification 1.200.848, the perylentetracarboxylic acid itself or its monoimid is obtained. The process gives let-red. hut he employed.

The following examples Wil the invention which however is Way confined to these examples.

The parts are h -J Weight.

(Tl) parts of the coloring matter obtained lay melting; naph'thalene-1.8-dicarlOGXVllC acid with caustic potash (the diimid of the neryientetracarhoxylic are heated with 150 parts of sulfuric acid of 66 36.

180 cent ade dur ,5 about i the mass has emaining 1 shout l illustrate in any Washed v d of 60 Application filed September 1, 1922. Serial No. 585,819.

The sodium salt of the perylentetracar boxylic acid being easier soluble than that of the mono-imid of the perylentetracarboxylic acid the two bodies may be separated in form of their sodium salts.

From the sodium salt the monoimid of the perylentetracarboxylic acid is precipitated by means of acids. When dried it is a redbrown powder soluble in very diluted solutions of alkali With an intense red color. From its alkaline solutions it is precipitated by means of small quantities of salt. In concentrated sulfuric acid it dissolves With a bluish-red color and a strong scarlet-red fluorescence. When heated with concentrated sulfuric acid ata higher temperature, it is transformed into the anhydride of perylentetracarboxylic acid.

(2) 1 part of the diimid of perylentecarboxylic acid (ctr. Example 1) is heated with 1045 parts of concentrated sulfuric acid. to about $10" centigi'ade. Thebluish-red color of the solution disappears and chan es to red-violet. At the same time darlz need es are separated. After some time the mass is suclred off and "washed. The brownish-red productobtained consisting of brown needles is the anhydride of the perylentetracarhoxylie acid.

The compound dissolves completely in alkaline agents in the heat With a brownish yellow color and a very strong fluorescence. The acid is precipitated from the alkaline solution l m neral acids in a yellowrown and voluminous form. On heating the precipitate becomes red.

The presence of the per ilentetracarhoxyiic acid is identified by the transformation of its calciumsalt into perylen. when heat= ed ina dry state. alkali-salts, especially the sodium-salt, are soluble only With dir'nculty.

The product obtained in the anhydride of a tetrachloroperylentetracarboxylic acid consisting of brownish-red glittering crystel-plates.

By the addition of ice to the acid motherlye a further quantity of the new-acid is precipitated.

The anhydride dissolves in alkali with a yellow color and green fluorescence. The alkali salts are easier soluble than those of the non-substituted acid. The calcium-salt is yellow and soluble only with difliculty.

If an alkaline solution of the tetrachlorinated acid is acidified in the cold the acid separates .at first with a yellowish color, Whereas on heating the orange-red anhydride is formed.

In concentrated sulfuric acid the anhydride dissolves with difliculty with a red color and scarlet-red fluorescence, in nitro-' benzene with a brownish-red color and' olive fluorescence.

We claim:

1. The process which consists in heating with a strong sulphuric acid an imid of a perylentetracarboxylic acid obtainable by melting an imid of a naphthalene-1.8-dicarboxylic acid.

2. As new products the anhydrides of the perylentetracarboxylic acids of the formula having a red-brown color, orystallizing in brown needles, soluble in alkaline agents with a yellow color of a strong fluorescence and in concentrated sulfuric acid with red color and orange-red fluorescence.

3. As new products the salts of the perylentetracarboxylic acids having a yellow color, being slightly soluble in water with a strong green fluorescence, being precipitated with acids in form of the free perylentetracarboxylic acid, changing into the corresponding anhydrides when heated.

4. As new productsthe monoimids of the perylentetracarboxylic acids of the following, formula ar ed.

being red to brown powders, soluble with an intense red color in diluted alkaline solutions from which they are precipitated by means of salts, soluble in.concentrated sulfuric acid with a bluish-red color and strong scarlet-red fluorescence, in which solution they are transformed into the an-. hydride of the perylentetracarboxylic acids when heated at a higher temperature.

In testimony whereof we aflix our signature in presence of two witnesses.

DR. WILHELM NEUGEBAUER.

DR. MAXIMILIAN P. SCHMIDT. Witnesses:

F. H. Annnneorr, BASIL E. Severn. 

